Flow Control Device

ABSTRACT

A valve assembly for a hot water service in a building joins a thermostatic valve  30  to a diaphragm vale  38 . This assembly diverts water from a domestic water heater which is cold or only warm and ensures hot flow without running water to waste. The assembly has a leg  14  which bypasses water at mains pressure for collection or garden use. The assembly is modified by joining the assembly in series with a tempering valve  44  which admits cold water flow to reduce the hot water temperature from 50° C.-60° C. to 44° C.

FIELD OF THE INVENTION

This invention concerns devices for delivering a liquid stream at apredetermined temperature. The invention will be described withparticular reference to supplying hot water facilities in buildings andsaving water in dwellings which have a hot water serice.

BACKGROUND OF THE INVENTION

Persons who wait for hot water to arrive at a tap or showerhead normallyrun the initial cold water to waste. As much as 10% of each servicecycle can be wasted in this way. In larger homes, the distance to thewater heater is longer. In older houses the pipe work insulation may beabsent or inferior. Modern in-line continuous flow gas water heatershave a time delay before achieving target temperature. All lead toincreased water loss. In winter the problem is exacerbated.

The bypass may direct cold water to a collector at the same waterpressure as the supply pressure. In gas or other water heatinginstallations this will be mains pressure, namely greater than 400 kPa.Such a feed pressure wil send water a useful distance in urban setting,for example a pool, a garden watering system, or storage tank. On ruralproperties the supply pressure will not have mains pressure but pumppressure or pressure created by a gravity feed header tank. The coldoutlet may therefore return water to the storage tank for re-use.

Devices have been proposed to bypass the cold water but they eitherrequire an electrical voltage powered device or they reduce the pressureof the saved water so that possibilities for its re-use are downgraded.

WO2004088051 describes a water recovery system in which bypass water isdiverted by a valve assembly until it is sufficiently hot and a venturisituated between the mains inlet and the mains outlet “sucks in”bypassed water from a storage tank and returns it to the system.

The aim of this invention is not to capture bypass water, but to make itavailable for use rather than running it to waste.

SUMMARY OF THE INVENTION

A valve assembly comprising

(a) a thermostatic valve having a hot inlet and hot outlet and a bypassoutlet for water which is not hot enough to gain passage between the hotinlet and the hot outlet,

(b) a separate diaphragm valve in series in the bypass outlet, whereinthe valve closes the bypass in response to an increase in pressure atthe hot water outlet.

The thermostatic valve maybe a wax element tempering valve connected forreverse operation. The diaphragm valve maybe connected by capillaryconduit to the hot outlet.

In this valve assembly the inlet/outlet connections of the assembly maybe substantially aligned and all point in the same direction.

The hot inlet of the assembly maybe connected to the hot inlet of abasin and the hot outlet maybe connected to conduits which service otherhot water outlets in the vicinity including the hot tap supplying thebasin while the bypass water is collected. Accordingly the assembly maybe fitted in the basin cabinet and plumbed into the other outlets in thebathroom such as the shower or bath. It may also be placed in anylocation adjacent to the multiple outlets to be supplied.

In a preferred embodiment, the hot outlet of the assembly is connectedto the hot inlet of a tempering valve which has a cold inlet for coolingthe hot flow and an outlet for tempered flow. The tempering valve may beadjustable to deliver tempered flow at 44° C. Placing the assembly in abasin cabinet allows access for repair anrd adjustment.

While a variety of hydraulic diaphragm valves are obtainable, we havetested a number of ½″ and ¾″ sizes and found that their response to arise in pressure following the ordinary closing of a hot water outlet inthe system effectively closes the bypass. As long as the elevation inpressure prevails, the diaphragm remains closed an “hunting” iseliminated. If the sytem has a domestic water supply where a long lifeis expcted it is useful to select a diaphragm valve with a diaphragm ofhigh grade ribber, butyl rubber or polyurethane in order to discouragewater borne bacteria from trying to metabolise the diaphragm.

BRIEF DESCRIPTION OF THE DRAWINGS

One enbodiment of the invention is now described with reference to theaccompanying drawings, in which:

FIG. 1 is a diagram of a domestic hot water service showing the bypasscomponent;

FIG. 2 is a plan view of the bypass component;

FIG. 3 is a flow diagram of the byass component;

FIG. 4 is a diagram of the byass component in series with a temperingvalve to achieve both water saving and a target temperature which meetsregulations;

FIG. 5 is a diagram of the bypass component in series with a temperingvalve to achieve both water saving an a target temprature which meetsregulations; and

FIG. 6 is a diagram of a domestic hot water service showing the bypasscomponent and temperature control sytem.

DETAILED DESCRIPTION

Referring now to FIG. 1, gas/electric/oil/wood/other heater 2 receives acold water supply 4 at mains pressure and through the wall via pipe 6.Hot water main 8 travels across the dwelling to washbasin 12. Hot main 8supplies bypass component 12. Bypassed cold water leaves component 12through pipe 14 which joins a drip irrigation system or other (notshown). Hot outlet 16 serves basin tap 18 and shower 20. Screw valve 22in the shower controls shower flow in known manner.

Referring now to FIG. 2, component 12 has three unions 24, 26, 28. Union24 admits hot water from hot water main 8 to the outlet of athermostatic valve 30 against the flow direction marked with the arrow.The valve contains a wax element and is a standarf pluming component.The COLD side marked “C” is connected to a bend 32 ad a stud 34 whichends union 26.

The HOT side marked “H” is connected via bend 36 to diaphragm valve 38which is also a standard plumbing component. One side of the diaphragmis connected by capillary tube 40 to stub 34. The cold bypass waterleaves union 28 to join pipe 14.

Referring now to FIG. 3, when the user opens valve 42, water from theheater issues at varing temperature and pressure. If the wax element isnot thermally activated, water enters at port A and leaves via port B tobypass. C is adjusted to open above a target temperature. As thearriving water rises in temperature, the wax element closes port B andopens port C. When vale 42 closes, pressure rises at port C via thecapillary tube and the diaphragm valve closes and remains closed untilvalve 42 reopens.

Whereas water heaters deliver water at the temperature set by thehouseholder which may vary between 40° C. and 80° C., regulationstipulates that the approved temperature should not exceed 50° C. Thiswill not harm a person's skin but is hot enough for domestic tasks suchas cleaning and laundry. This temperature however is generally too hotto shower under, therefore our target temperature is 44° C. which is asafe and comfortable temperature.

In FIG. 4, an assembly is shown which uses mains hot and cold water andbypasses water during the warm up period. Thus the assembly is intendedto deliver hot water at a uniform temperature. To this end the bypasscomponent 12 receives flow at 50° C. or greater from hot main 8. Coldand warm water leave the assembly through byass 14. Hot water leavescomponent 12 through stub 34 and enters tempering valve 44. Cold main 4supplies sufficient flow to reduce the temperature by a few degrees. Thehot flow is delivered by tempering valve 44 at 44° C. In FIG. 4 thetempering valve is connected to hot and cold flows the conventional wayround.

FIG. 5 slows an alternative configuration to the FIG. 4 assembly. Thethermostatic valve 30 and diaphragm valve are arranged as in FIG. 4 butthere are four unions.

Referring now to FIG. 6, gas/electric/oil/wood/other heater 2 receives acold water supply 4 at mains pressure and through the wall via pipe 6.Hot water main 8 travels across the dwelling to washbasin 10. Hot main 8supplies bypass component 12. Bypassed cold water leaves component 12through pipe 14 which joins a drip irrigation system or other (notshown). Cold water from main 6 enters temperature control module 44where it is mixed with hot water from 12 which is delivered to pipe 16at target temperature of 44° C. approximately to serve basin 18, shower22 and bath 24 via screwvalves to control water flow in known manner.

I have found the advantages of the above embodimnent to be:

1. The assembly utilises components of already proven reliability.

2. The use of separate thermostatic and hydraulic valves cheapensreplacement and repair.

3. The tempered supply is adjustable to deliver hot water at 44° C.

4. The bypassed water is available at mains pressure.

5. Is suitable for use with all types of tapware.

6. No external power source is required.

7. No sound.

8. Suitale for use with non-storage type water heaters (i.e. gascontinuous flow).

1. A Be assembly comprising: (a) a thermostatic valve having a hot inletand hot outlet and a normally open bypass outlet for water which is nothot enough to gain passage between the hot inlet andthe hot outlet; and(b) a seperate diaphragm valve in series in the bypass outlet, whereinthe valve closes the bypass in response to an increase in pressure atthe hot water outlet.
 2. A valve assembly as claimed in claim 1, whereinthe thermostatic valve is a wax element tempering valve connected forreverse operation.
 3. A valve assembly as claimed in claim 1, whereinthe diaphragm valve is connected by capillary conduit to the hot outlet.4. A valve assembly as claimed in claim 1, wherein the inlet and outletand bypass terminate in pipe connectors which are substantially aligned.5. A valve assembly as claimed in claim 4, wherein the connectors allpoint in the same direction.
 6. A valve assembly as claimed in claim 1,wherein the thermostatic valve is connected in series to a temperingvalve having a hot inlet a cold inlet and a mixed outlet for temperedflow, the hot outlet of the thermostatic valve being connected the hotinlet of the tempering valve.
 7. A valve assembly as claimed in claim 5,wherein the tempering valve is adjustable to deliver tempered flow about44° C.
 8. A hot water service comprising a basin served by a hot watersupply and a valve assembly in turn comprising: (a) a thermostatic valvehousing a hot inlet for water from the hot water supply; (b) a hotoutlet directing water to the basin; (c) a normally open bypass forwater which is not enough to gain passage between the hot inlet and hotoutlet; and (d) a separate diaphragm valve in series in the bypassoutlet, wherein the valve closes the bypass in response to an increaseinl pressure at the hot water outlet.
 9. A hot water service as claimedin claim 8, wherein the hot outlet directs hot water to another hotwater outlet in the vicinity.
 10. A hot water service as claimed inclaim 9, wherein the hot water outlets in the vicinity serve a showerand a bath.